The requirements relating to the output and efficiency of internal combustion engines are becoming increasingly stringent. At the same time strict legal provisions require pollutant emissions to be kept at low levels. To this end it is known that internal combustion engines can be fitted with a phase adjusting device, which can be used to modify a phase between a crankshaft and a camshaft of the internal combustion engine during operation. The respective start and end of the opening or closing of the gas inlet and/or gas outlet valve can thus be modified in relation to a reference point on the crankshaft. This allows the level of gas in a cylinder to be modified; in particular it is possible for exhaust gas to be fed back internally into the respective cylinder.